Coupling fields with single conductor through-switching of extensions over electromagnetically actuated contacts



Sept. 6, 1966 Filed Sept. 28, 1960 Kal KaZ

K. KARRER COUPLING FIELDS WITH SINGLE CONDUCTOR THROUGH- SWITCHING 0F EXTENSIONS OVER ELECTROMAGNETICALLY ACTUATED CONTACTS Fig. I

KbZ

2 Sheets-Sheet 1 Sept. 6, 1966 K. KARRER 3,271,523 COUPLING FIELDS WITH SINGLE CONDUCTOR THROUGH-SWITCHING 0F EXTENSIONS OVER ELECTROMAGNETICALLY ACTUATED CONTACTS Filed Sept. 28, 1960 2 Sheets-Sheet 2 United States Patent 3,271,523 COUPLING FIELDS WITH SINGLE CONDUCTOR THROUGH-SWITCHING 0F EXTENSIONS OVER ELECTROMAGNETICALLY ACTUATED CON- TACTS Korbinian Karrer, Munich, Germany, assignor to Siemens & Halske Aktiengesellschaft Berlin and Munich, a corporation of Germany Filed Sept. 28, 1960, Ser. No. 59,029 Claims priority, application Germany, Oct. 14, 1959, S 65,425 11 Claims. (Cl. 17922) This invention is concerned with coupling fields for communication systems and especially telephone systems utilizing single conductor through-switching of the speech current path extending over electromagnetically actuated sealed-in contacts. Coupling fields are sometimes also referred to a cross-wire circuits.

The various objects and features of the invention will be brought out in the course of the description which will be rendered below with reference to the accompanying drawings.

FIG. 1 shows in schematic manner a known coupling field to aid in understanding the principles involved in the construction thereof;

FIG. 2 illustrates a circuit constructed according to the invention;

FIG. 3 represents a portion of a layer of a coupling multiple.

Coupling fields often include a plurality of coupling stages, each built up of socalled coupling multiples, wherein the individual coupling points, to which are connected the coupling contacts, are respectively row-wise and column-wise connected in multiples.

A known coupling field of this kind is shown in principle representation in FIG. 1. It contains three coupling stages A, B and C, each stage having a plurality of coupling multiples as indicated respectively at Kai-KaS, Kb1-Kb3 and Kcl-Kc3.

The coupling multiples are in known manner interconnected over trunk lines Z. A connection path is indicated as extending over closed coupling contacts ka, kb and kc. All other coupling contacts have been omitted to keep the drawing simple.

Coupling fields of this kind are customarily provided with three-conductor or four-conductor connections, two conductors serving for the talking path and the remaining conductor or conductors as private or control conductors for the building up of connections. This also includes the requirement according to which closed coupling contacts must be maintainedin closed condition for the duration of a connection. For this purpose, special holding coils have been provided, until now, such holding coils being connected to one of the private or control conductors and holding the respectively involved coupling contacts in actuated condition so long as current flows over the corresponding private or control conductor.

The principal object of the invention is to provide coupling field systems with single conductor throughswitching over electromagnetically actuated coupling contacts. This object is according to the invention realized by connecting in series with each coupling contact of the one conductor a holding coil which holds the corresponding coupling contact in closed condition depending upon current flowing over such conductor.

FIG. 2 shows a circuit constructed according to the principle of the present invention, such circuit representing a connection between two subscriber stations T1 and T2 which are respectively connected to the network over transformers U1 and U2. The net work which is indicated fractionally, may be in the form of a coupling field 3,271,523 Patented Sept. 6, 1966 such as is indicated in FIG. 1. The network includes the three coupling stages A, B, C, FIG. 2 showing however only the coupling contacts ka, kb, kc of these stages over which a connection may be extended. Each of these coupling contacts ka, kb, kc has a holding coil respectively indicated at Ha, Hb, Hc, serially related thereto. When a call or connection is switched through, which is in known manner efiected by means of devices such as markers, etc., customarily employed in coupling field systems, there will be formed a closed circuit including a current source S. The current supplied by this source energizes the holding coils Ha, Hb, Hc, such holding coils being effective to maintain their respectively associated contacts ka, kb, kc in closed condition and thereby maintaining the corresponding connection. The release operation which takes place in known manner upon termination of the call causes opening of the circuit extending over the single conductor connection, thereby effecting release of the holding coils and consequently restoration of the coupling contacts into normal position.

The holding coils which are according to the invention inserted in the one conductor can also be used as energizing coils. Marker lines are for this purpose extended to the holding coils, as shown in FIG. 2, and such marker lines are placed on current so as to cause energization of the respective holding coils and therewith operative actuation of the coupling contacts associated therewith. More in detail, marker lines M1 extend from the respective holding coils Ha, Hb, Hc over switch-in contacts x to a marker M. The contacts at serve for connecting the marker always to the coordinate switch at which a switching-through operation is to be effected. Contacts of this kind, for the purpose stated, are customary in communication systems employing coordinate switches; they have no particular bearing on the invention. The marker controls in known manner the building up of connections by placing current on the respective marker lines M1, thereby effecting the closure of the various coupling contacts. Upon completing the building up of a connection, there will be present a holding circuit which is supplied from the battery S to maintain the connection.

The arrangement according to the invention can also be utilized in connection with socalled relay coupling fields having for each coupling point an energizing coil for the actuation of the corresponding contact and a holding coil for maintaining the contact actuated. It is however also possible to use the invention in connection with a coupling field having for each contact a holding coil and two energizing coils which are respectively associated with the respective coordinate directions, the energization of these two energizing coils causing operative actuation of the corresponding contact. Among structures of this kind may be mentioned the socalled cross coil switches, an example of which is described in the copending application Serial No. 573,039 filed March 21, 1956.

A particularly advantageous structure will be obtained upon using sealed-in contacts to operate as coupling contacts. These sealed-in contacts, sometimes also referred to as protective tube contacts, are distinguished by hermetically enclosed contact points, permitting moreover combining of the energizing coils of at least one coordinate direction in one elongated coil which embraces the entire coordinate, as is also the case in the socalled cross-coil switches. The holding coils employed in such structures also have relatively short average turns and therewith a relatively low ohmic resistance.

An arrangement of this kind is shown in FIG. 3 which represents a portion of a layer of a coupling field. A complete coupling field is obtained by placing such layer one above the other. In the illustrated arrangement, there are employed contacts of the dry-reed type as coupling contacts, only the contact springs F of such contacts being shown to keep the drawing simple. At the working air gap L of the respective contact springs F is disposed a holding coil H, the energization of which suffices to maintain a closed contact in closed position. Energizing coils are arranged at the ends of the respec tive holding coils H, such energizing coils being desig nated by X and Y according to the respective coordinate directions. As will be seen from the figure, there is provided in the direction of the coupling field an X coil for each contact while a Y coil extends in the Y direction over the entire layer. The X coils are in the respective columns electrically serially related as indicated by dot-dash lines. The energization of a Y coil and an X coil, which is in the illustrated case effected column-Wise and row-wise, causes operative actuation of the respective contacts. The energization of the Y-coil and of the X-coil can be effected in known manner by a marker, for example, in a manner similar to the actuation of a rod and a bridge of a crossbar switch under control of a marker. FIG. 2 also shows two marker lines M1 per coupling point, which can be utilized for the energization of the X and Y coils, respectively. The corresponding actuated contact establishes a current path extending over the respective holding coil H as such holding coil is serially connected with the respectively associated contact spring P, such connection being indicated by the dot-dash line V. The speech current path then extends over the involved holding coil H and the dot-dash line V to the end of the respective contact spring F, from there over the closed working air gap L to the other contact spring, and from the latter to the next stage.

In order to fully utilize the sensitivity of the sealed-in contacts, the fixedly disposed ends of the contact springs F are magnetically interconnected over return path members R, such return path being of course electrically insulated from the contact springs. As is apparent from FIG. 3, these return path members extend respectively each over a layer of the coupling field. The direction of the layers coincides with the direction of the common energizing coils, in the illustrated example, the Y coils. There will thus result individual complete switch layers which are not interrupted by any structural elements as, for example, by coils extending therethrough. The advantage is that any desired number of layers can be produced for such structure without difficulties.

Since the holding coils are disposed in the speech current path, as shown in FIG. 2, they produce due to inductivity thereof, a certain damping. This may be remedied by connecting capacitors in parallel to the holding coils. Another possibility of reducing the clamping resides in providing the holding coils with short-circuit windings, thereby eliminating the necessity for an auxiliary structural element such as a capacitor. The shortcircuit winding may be provided in the form of an electrically conductive sleeve upon the respective holding coils, such sleeve being indicated in FIG. 3 at D. Another possibility of producing the short-circuit winding resides in providing it in the form of a ring adjacent the holding coil or at its two ends, respectively.

The principle of using the holding coils as energizing coils, as illustrated in FIG. 2, can be readily applied in FIG. 3, and the structure will then be provided only with holding coils acting also as energizing coils, thus eliminating separate energizing coils.

Changes may be made within the scope and spirit of the appended claims which define what is believed to be new and desired to have protected by Letters Patent.

I claim:

1. In a coupling field employed in a communication system, an arrangement for switching through connections over a single conductor of the speech current path extending over electromagnetically controlled coupling contacts, comprising a holding coil disposed in serial relationship with respect to each coupling contact, and circuit means opera-tively directing current flowing over said single conductor to the respective holding coils to energize the same and thereby maintain the coupling contacts respectively associate-d therewith in actuated condition.

2. An arrangement according to claim 1, wherein said coupling contacts are parts of relay coupling fields.

3. An arrangement according to claim 1, comprising two energizing coils for each coupling contact, said energizing coils belonging respectively to the two coordinate directions of the arrangement.

4. An arrangement according to claim 3, wherein said coupling contacts are of the dry-reed type.

5. An arrangement according to claim 4, wherein the energizing coils of at least one coordinate direction are combined in an elongated coil which embraces the entire respective coordinate.

6. An arrangement according to claim 5, wherein said holding coils embrace the working air gaps of the respective contacts and wherein said energizing coils are disposed at the ends of the respective holding coils.

7. An arrangement according to claim 1, wherein said holding coils are utilized as energizing coils for the respec tive coupling contacts.

8. An arrangement according to claim 4, comprising magnetic path means extending respectively over layers of the coupling field for magnetically interconnecting the fixedly disposed ends of the coupling contact springs.

9. An arrangement according to claim 5, comprising magnetic return path means extending respectively over layers of the coupling field for magnetically interconnecting the fixedly disposed ends of the coupling contactsprings, said return path means extending over layers defined respectively by said elongated energizing coils.

10. An arrangement according to claim 1, comprising means for each holding coil constituting a short-circuit winding therefor.

11. An arrangement according to claim 10, wherein said last named means is in the form of an electrically conductive sleeve cooperatively disposed with respect to the corresponding holding coil.

References Cited by the Examiner UNITED STATES PATENTS 241,184 5/1881 Bell 179--1 2,187,115 1/ 1940 Ellwood et al 179-27.54 2,299,203 10/1942 Beaumont 1'7922 2,397,123 3/1946 Brown l7927.5 2,768,241 10/1956 Hutton 179-22 2,954,440 9/1960 Williams 179-22 3,033,939 5/1962 Nitsch 179-2754 3,053,938 9/1962 Nitsch 17927.54

KATHLEEN H. CLAFFY, Primary Examiner.

L. MILLER ANDRUS, WALTER L. LYNDE, STEPHEN W. CAPELLI, H. BOOHER, Examiners.

L. A. WRIGHT, Assistant Examiner. 

1. IN A COUPLING FIELD EMPLOYED IN A COMMUNICATION SYSTEM, AN ARRANGEMENT FOR SWITCHING THROUGH CONNECTIONS OVER A SINGLE CONDUCTOR OF THE SPEECH CURRENT PATH EXTENDING OVER ELECTROMAGNETICALLY CONTROLLED COUPLING CONTACTS, COMPRISING A HOLDING COIL DISPOSED IN SERIAL RELATIONSHIP WITH RESPECT TO EACH COUPLING CONTACT, AND CIRCUIT MEANS OPERATIVELY DIRECTING CURRENT FLOWING OVER SAID SINGLE CONDUCTOR TO THE RESPECTIVE HOLDING COILS TO ENERGIZE THE SAME AND THEREBY MAINTAIN THE COUPLING CONTACTS RESPECTIVELY ASSOCIATED THEREWITH IN ACTUATED CONDITION. 